1. Field of the Invention
This invention relates in general to digital data processing, and more particularly to a technique for obviating bits within a bit stream which are dedicated to the identification of the start and end of the various bytes which are formed by the bits within such bit stream.
2. Description Relative to the Prior Art
A digital data bit stream is (usually) comprised of a succession of bytes, each having the same number of bits per byte. Unless some provision is made to distinguish the start and end of each given byte, apparatus responsive to the bit stream will be unable to discern whether a given bit is a "most significant bit", a "least significant bit", or a bit somewhere between the most and least significant bits. Were, for example, an apparatus responsive to 8 bit bytes to receive--firstly--the fifth most significant bit of a byte, then the fourth most significant bit of that byte, then the third, and so on, it would wind up interpreting five bits from one byte and three bits from the next occurring byte as its 8 bit input . . . and attendantly the apparatus in question would operate incorrectly.
To reconcile this problem, it is the practice in the art to separate each byte of a bit stream from its adjacent bytes by means of a specially coded sequence of bits constituting "sync" for the bit stream. Typically, about ten percent of the bits in a bit stream containing sync bits are dedicated to the definition of sync. Such use of sync-defining bits, aside from requiring circuit apparatus for interleaving, and then de-interleaving, the information bits and the snyc bits, means inefficiency, and an increase in the bandwidth associated with the bit stream; corollarily, given a finite bandwidth for the data processing channel in question, this attendantly means that the capacity of the channel processing the bits is less than it would be otherwise.